git/http.h
Jeff King 2501aff8b7 http: hoist credential request out of handle_curl_result
When we are handling a curl response code in http_request or
in the remote-curl RPC code, we use the handle_curl_result
helper to translate curl's response into an easy-to-use
code. When we see an HTTP 401, we do one of two things:

  1. If we already had a filled-in credential, we mark it as
     rejected, and then return HTTP_NOAUTH to indicate to
     the caller that we failed.

  2. If we didn't, then we ask for a new credential and tell
     the caller HTTP_REAUTH to indicate that they may want
     to try again.

Rejecting in the first case makes sense; it is the natural
result of the request we just made. However, prompting for
more credentials in the second step does not always make
sense. We do not know for sure that the caller is going to
make a second request, and nor are we sure that it will be
to the same URL. Logically, the prompt belongs not to the
request we just finished, but to the request we are (maybe)
about to make.

In practice, it is very hard to trigger any bad behavior.
Currently, if we make a second request, it will always be to
the same URL (even in the face of redirects, because curl
handles the redirects internally). And we almost always
retry on HTTP_REAUTH these days. The one exception is if we
are streaming a large RPC request to the server (e.g., a
pushed packfile), in which case we cannot restart. It's
extremely unlikely to see a 401 response at this stage,
though, as we would typically have seen it when we sent a
probe request, before streaming the data.

This patch drops the automatic prompt out of case 2, and
instead requires the caller to do it. This is a few extra
lines of code, and the bug it fixes is unlikely to come up
in practice. But it is conceptually cleaner, and paves the
way for better handling of credentials across redirects.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
2013-10-14 16:55:13 -07:00

199 lines
5.4 KiB
C

#ifndef HTTP_H
#define HTTP_H
#include "cache.h"
#include <curl/curl.h>
#include <curl/easy.h>
#include "strbuf.h"
#include "remote.h"
#include "url.h"
/*
* We detect based on the cURL version if multi-transfer is
* usable in this implementation and define this symbol accordingly.
* This is not something Makefile should set nor users should pass
* via CFLAGS.
*/
#undef USE_CURL_MULTI
#if LIBCURL_VERSION_NUM >= 0x071000
#define USE_CURL_MULTI
#define DEFAULT_MAX_REQUESTS 5
#endif
#if LIBCURL_VERSION_NUM < 0x070704
#define curl_global_cleanup() do { /* nothing */ } while (0)
#endif
#if LIBCURL_VERSION_NUM < 0x070800
#define curl_global_init(a) do { /* nothing */ } while (0)
#endif
#if (LIBCURL_VERSION_NUM < 0x070c04) || (LIBCURL_VERSION_NUM == 0x071000)
#define NO_CURL_EASY_DUPHANDLE
#endif
#if LIBCURL_VERSION_NUM < 0x070a03
#define CURLE_HTTP_RETURNED_ERROR CURLE_HTTP_NOT_FOUND
#endif
#if LIBCURL_VERSION_NUM < 0x070c03
#define NO_CURL_IOCTL
#endif
/*
* CURLOPT_USE_SSL was known as CURLOPT_FTP_SSL up to 7.16.4,
* and the constants were known as CURLFTPSSL_*
*/
#if !defined(CURLOPT_USE_SSL) && defined(CURLOPT_FTP_SSL)
#define CURLOPT_USE_SSL CURLOPT_FTP_SSL
#define CURLUSESSL_TRY CURLFTPSSL_TRY
#endif
struct slot_results {
CURLcode curl_result;
long http_code;
};
struct active_request_slot {
CURL *curl;
int in_use;
CURLcode curl_result;
long http_code;
int *finished;
struct slot_results *results;
void *callback_data;
void (*callback_func)(void *data);
struct active_request_slot *next;
};
struct buffer {
struct strbuf buf;
size_t posn;
};
/* Curl request read/write callbacks */
extern size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
extern size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
extern size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf);
#ifndef NO_CURL_IOCTL
extern curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp);
#endif
/* Slot lifecycle functions */
extern struct active_request_slot *get_active_slot(void);
extern int start_active_slot(struct active_request_slot *slot);
extern void run_active_slot(struct active_request_slot *slot);
extern void finish_active_slot(struct active_request_slot *slot);
extern void finish_all_active_slots(void);
extern int handle_curl_result(struct slot_results *results);
#ifdef USE_CURL_MULTI
extern void fill_active_slots(void);
extern void add_fill_function(void *data, int (*fill)(void *));
extern void step_active_slots(void);
#endif
extern void http_init(struct remote *remote, const char *url,
int proactive_auth);
extern void http_cleanup(void);
extern int active_requests;
extern int http_is_verbose;
extern size_t http_post_buffer;
extern struct credential http_auth;
extern char curl_errorstr[CURL_ERROR_SIZE];
static inline int missing__target(int code, int result)
{
return /* file:// URL -- do we ever use one??? */
(result == CURLE_FILE_COULDNT_READ_FILE) ||
/* http:// and https:// URL */
(code == 404 && result == CURLE_HTTP_RETURNED_ERROR) ||
/* ftp:// URL */
(code == 550 && result == CURLE_FTP_COULDNT_RETR_FILE)
;
}
#define missing_target(a) missing__target((a)->http_code, (a)->curl_result)
/* Helpers for modifying and creating URLs */
extern void append_remote_object_url(struct strbuf *buf, const char *url,
const char *hex,
int only_two_digit_prefix);
extern char *get_remote_object_url(const char *url, const char *hex,
int only_two_digit_prefix);
/* Options for http_get_*() */
struct http_get_options {
unsigned no_cache:1,
keep_error:1;
/* If non-NULL, returns the content-type of the response. */
struct strbuf *content_type;
};
/* Return values for http_get_*() */
#define HTTP_OK 0
#define HTTP_MISSING_TARGET 1
#define HTTP_ERROR 2
#define HTTP_START_FAILED 3
#define HTTP_REAUTH 4
#define HTTP_NOAUTH 5
/*
* Requests a URL and stores the result in a strbuf.
*
* If the result pointer is NULL, a HTTP HEAD request is made instead of GET.
*/
int http_get_strbuf(const char *url, struct strbuf *result, struct http_get_options *options);
extern int http_fetch_ref(const char *base, struct ref *ref);
/* Helpers for fetching packs */
extern int http_get_info_packs(const char *base_url,
struct packed_git **packs_head);
struct http_pack_request {
char *url;
struct packed_git *target;
struct packed_git **lst;
FILE *packfile;
char tmpfile[PATH_MAX];
struct curl_slist *range_header;
struct active_request_slot *slot;
};
extern struct http_pack_request *new_http_pack_request(
struct packed_git *target, const char *base_url);
extern int finish_http_pack_request(struct http_pack_request *preq);
extern void release_http_pack_request(struct http_pack_request *preq);
/* Helpers for fetching object */
struct http_object_request {
char *url;
char tmpfile[PATH_MAX];
int localfile;
CURLcode curl_result;
char errorstr[CURL_ERROR_SIZE];
long http_code;
unsigned char sha1[20];
unsigned char real_sha1[20];
git_SHA_CTX c;
git_zstream stream;
int zret;
int rename;
struct active_request_slot *slot;
};
extern struct http_object_request *new_http_object_request(
const char *base_url, unsigned char *sha1);
extern void process_http_object_request(struct http_object_request *freq);
extern int finish_http_object_request(struct http_object_request *freq);
extern void abort_http_object_request(struct http_object_request *freq);
extern void release_http_object_request(struct http_object_request *freq);
#endif /* HTTP_H */